This invention relates to well tools and, particularly, to a flow control apparatus and a mandrel support for such apparatus of the side-pocket type for use in a well pipe or tubing.
Various pressure control techniques for high pressure wells utilize a circulating (kill) valve near the bottom of a tubing string that permits heavy drill weight and light completion weight fluids to be displaced from the tubing-casing annulus and tubing flow conduit after a packer sealing and tubing-casing annulus has been set. The circulating valve must close and remain pressure sealed after pumping operations are complete and be capable of reopening when necessary for additional well control fluid circulation operations. The failures of available circulating (kill) valves are aggravated by opening and closing manipulating operations, metal erosion caused by the circulating fluids, and high temperature and well environmental effects on nonmetallic valve sealing components.
The present invention provides an improved pressure operated downhole circulating (kill) valve which alleviates the primary causes of problems with that type valve. This circulating valve is not only useful in downhole circulating well-kill operations, it also has use as a chemical injector valve and in other well operations where it is desired to circulate fluid between well pipes.